These are the symptoms I am experiencing, it sounds like you have the same problem.
Replacing the secondary filter housing seems like a permanent fix providing there is no other air leaks
, at least from the reports I am hearing. As I have redone my entire fuel system and replaced every component at least once so I am expecting a permanent fix from the change.
Yanmar are sourcing replacement components, but at the moment they are out of stock.
I will certainly report on the success (or otherwise) of the change.